Armature recutting tool



Jan. 23, 1940. A, BURRQWS ET AL 2,187,874

ARMATURE RECUTTING Tool. A Fim; Aug. 9, 1937 2 sneets-sheet 1 AIL E 49 '11 r w: v u I A A MLM W L L 7 INV ENT ORJ` M meM-Wm Jan. 23, 1940.

' ARMATURE REGUTTING 'rooL Filed Aug. 9, 1937 2 Sheets-Sheet 2 MYMWWWLW; M@

* ATTORNEY.

A. BuRRowS ET A1. 2,18'7'874 ai. adapted for cutting ortrueing armatures of genr3. erators and similar devices ,whichE comprise a shaft which projects through and carries an,

Patented Jan. 23, 1940 s iifrlATlS-:INT g oFF-ics l 2,187,874l v 'ARMATUR REQUTTING Toon "Allen Burrows, Brockton, and Walter H. --Rhindres's, BraintreeMass.

This invention relates .to vtools particularlyvd armature including a commutator which consists of a.cylinder, the curved surfaceof which is A lformed of strips or sections 4of copper or ,otherg good conducting material separated b-y strips of ordinary vise with the armature and shaft 'stickmica or other insulatingxmaterial. commutators of armatures are worn downv by the'.l brushes, it is desirable, especially when they come from automobiles, that the whole device 'shoulda be takenv out vwith the armature on the .shaft and 'to .cut the armature cylinderv in a new and perfect circle. f

This tool is of such a character that when such a generator is taken out, it can-be heldin `any ing out and this tool can 13e-quickly. attached to; the projecting shaft in such' aimanner that a cutter can be quickly ,adjusted and can/then be.

' depth.

turned. by a hand Wheel so that it cuts spirally around the curved surface of the armature progressing. all the timeuntil the cutting is entirely,

finished. It can then be usedin such a way that .the cutter. is caused to travel parallel with.-

the axis instead of circumferentially to cutiv down the isinglass or other insulations to the desired` j This tool.. can V.be `used successfullyflwith any generator,y starterA motor i or other electrical', machine in which there is a cylindrical armav turef-commutator carried by a shaft which sticks tator'and revolvingr against astationary tool, We.-r

fout from it with a smooth,fcy1indrical, end. ff,

Insteadoffcentering such ashaft and comn1u hold the device in a vise or in any other kind of holder with the shaft and commutator sticking out and then attachthis tool tothe shaft, aftery which part of the tool revolves, carryingathe cut-f f1 N loosened from the hole 4.

ting element. 1 We use a cylinder which we afx to the shaft and provide a rider slidable on Athis cylinderand. a. turnable member. which f'eng'agesfthe fscrewf threadsfin 'thecylinder'and which is detachable.v

from the rider. Bfy'us'ing a rider and turnable.; member detachably locked together, they do their cutting together, but when the cutting is finished, they can be separated, the turnable member being quickly spun back out of the way and the rider with the cutting :member can be slipped back parallel with the axis and without revolving the cutter` backward in a spiral, a procedure which is objectionable.

In the drawings,

Fig. 1 is afro-nt elevation of ojuyrtool in position ,operating .on an armature commutator of a generator vwhichisheld in place by a vise on a bench. Y l5ig. 2 showsin section the various parts which" make up the tool.

- Fig. -3 is a vertical section on aplane through theshaft `and axis of the tool. f

Whensuch 4, 4 in Fig. 1 lookingin the direction'of the arrow.

Fig. 4 -isan enlargedsectional view on the line Fig. 5 is asectional view on a vertical plane through vthe-axis of a modification of the cylinder.

Fig. 6 is afview. similar to Fig. 3 of another modification.

f Fig. 7 is angisometriccview of a split bushing .;such as we. use, theltaper beingexaggerated.

Fig. 8 is airontelevation `showingthe rider dis y connected from lthe hand wheel and the manner vin which it cutsthe insulation. i

' Fig. 9 is a View similar to 3', onv a larger v scale, showing .a modified form.

In Ythe drawings, G represents a generator such as ,is Aused' iny automobiles. This generator is shown in-Fig. 1 as being held in an ordinary `vise V on bench L in'such agmanner that the armalture and `cormnutator M and itsy shaft S project .beyond the bench.

N is a split bushing or clampof the tapering L type. 'i The split is indicated by; 2 and the cylindrical hole. through it which engages shaft S is indicated by -3A while'the tapered surfaceis indicated by 22. I

rThisbushing Nwent'ers a tapered hole-4 in the supporting cylinder P which, as shown, is provided with the two holes 44, 44. Holes 44, 44 are so ylocatedthatt'hey are at the end of bushing N whenitis in' place. Bushing N can be pressed or tapped in place in hole 4 andv when .it isy desired toidisconnectzthem, a rod'or chiselzcan'be pushed in through one of the holes 44 and the-bushing Atitheotherl-end of the-cylinder P is an internallythreaded .hole 5, thethreads ycorresponding fwiththethreadson a screw shaft 'l-carried by and xed to a-han'd wheel vH as bya pin il.v As

@shownyfthefhub D of :wheel H hasrin Aone face 20 B is a rider through which is a hole l2 of just the size to make a smooth, running fit with the outside of cylinder P. Radially projecting from the end nearest Wheel I-I is a locking pin 9 which can be engaged and disengaged by a latch I9 carried by the hub D of wheel H. As shown, this latch includes a hook member 29, spring 30 and handle 3|.

By pushing handle 3i and hook 29 in from face 20 and bringing hub D and rider B together and turning them until pin 9 and hook 29 engage,

spring 3U will hold the parts quickly detachably` together.

Rider B has a projection 4U through which is a carrier recess 4| parallel with its axis. V is a cutter holder in recess 4| and. as shown, is

pivoted at d5 and provided with the adjusting screws 48 and 41 by which -it can be adjusted radially. Its other end is split at 13S toreceive a cutter or cutter tool T which is held in place by a tightening bolt 49.

In doing the cutting, the cutter, cutter holder, rider and handwheel or turnable member move forward spirally together but when the cutting.

is finished, the latch I9 is released from pin 9 when the handwheel can be lspun backward very quickly on the threads 5 and 6, after which the cutting tool, cutter holder and rider can be slipped back on cylinder P. The cutting tool T, preferably at one end 50, has a cutting edge which can be used in cutting around the surface of the vcommutator and at the other end 5|, a narrower cutting edge which can be used to cut the insulation when the parts are unlocked, as shown in Fig. 8. To do this cutting,` the rider separated from the hub D, can be and is pushed back and forth axially onthe cylinder P.

The wheel and hub can remain in place, as

shown by the full lines in Fig. 3. The cutting tool T is reversed to bring the narrow cutting end 5| in position to enter the space between the copper strips. The tool is so adjusted that this end 5| enters to the right depth and the rider and the tool are then moved by hand from the dotted position to the full line position, thus cutting down the insulation to the desired depth below the surface of the conducting elements.

Instead of a split tapered bushing such as N at the end of a cylinder such as P, we might use a clamp O located in a hole 50 in the end of a cylinder V, similar to P, except that the shaft hole 6| which is concentric with hole 50 would be of just the size to fit the end of shaft S. As shown, clamp O has two or more jaws such as 63, 63 projecting from the end of cylinder V which snugly fit shaft S, and are threaded on the outside with a slightly tapering thread 64 so that the ring nut 65 can be screwed out on them, thus tightening jaws 63 on shaft S to prevent it from turning with the hand wheel and rider. As shown in Fig. 6, I might use a cylinder such as C having at one end a tapered hole 14 or a bushing and at the other end 15, instead of inside threads, having the outside threads 1| which engage internal threads 12 on the hub I3 of a hand wheel 10. When this hand Wheel is turned, it moves a rider such as R in the same way as in the first described construction.

In Fig. 9, We show several modifications embodying the same principle. In some cases where there is a very long armature shaft such at 83, we nd it desirable to make the cylinder 80 threaded inside a hub such as 8| with a hole 82 entirely through it and of a size to permit the entry of shaft 83.

In this view also is shown the rider 84 as an integral part of the hub 8|; As with this construction the rider can not be separated from the hub and moved axially to cut the insulation between the metal strips of the commutator, the cutting tool, such as 85, has only a transverse cutting end shown at 95.

In this construction also, the pivot 86 for the vcutter holder 81 is at the end opposite tool 85 and the adjustment is made by means of a threaded post 88 around which is a compression spring 89 which tends to lift the cutter holder.

Thumb nut 90 works against the spring 89 and when the right adjustment is secured, a set screw 9| in the side holds the parts in rigid adjustment. f The supporting cylinder can be smooth on the outside as P, part threaded as C or 80, and detachable from or integral with the turnable `member such as the wheel and hub.

We claim: '"f

l. In a tool for recutting commutators of armatures which are mounted on a shaft; the combination of a supporting cylinder having at one end means to attach it to the shaft and at the other end an internally threaded hole with the axes of the attaching means, the shaft, the cylinder and the hole coinciding; with a rider slidable and revoluble on the cylinder and provided with a locking pin and a cutter carrier recess; a hand wheel which carries a, screw shaft in ergagement with the threaded hole in the cylinder and a locking latch in engagement with the locking pin; and a cutter holder pivoted in the recess and including means to adjust it radially and to hold it in place and means to hold a cutter in a position beyond the holding cylinder.

2. In a tool for recutting commutators of armatures which are mounted on a shaft with a smooth projecting cylindrical end; the combination of a supporting cylinder having at one end clamp means to x it to the shaft and at the other end an internally threaded hole with the axes of the attaching means, the shaft, the cylinder and the hole coinciding; with a rider axially slidable and revoluble on the cylinder and provided With a locking pin and a cutter carrier recess; a hand Wheel which carries a screw shaft in engagement with the threaded hole in the cylinder and a locking latch in engagement with the locking pin; and a cutter holder pivoted in the recess and including means to adjust it radially and to hold it in place and means to hold a cutter in a position beyond the holding cylinder.

AILEN BURROWS. WALTER H. RI-HNDRESS. 

